Straube and Bach

Bach in Mind

François Bach and André Herbelin

A conserved Bach current

The Bach tensor and a vector which generates conformal symmetries allow a conserved 4-current to be defined. The Bach 4-current gives rise to a quasilocal 2-surface expression for power per luminosity distance in the Vaidya exterior of collapsing fluid interiors. This is interpreted in terms of entropy generation. PACS numbers: 0420J, 0440N

Null Surfaces and the Bach Equations

It is shown that the integrability conditions that arise in the Null Surface Formulation (NSF) of general relativity (GR) impose a field equation on the local null surfaces which is equivalent to the vanishing of the Bach tensor. This field equation is written explicitly to second order in a perturbation expansion. The field equation is further simplified if asymptotic flatness is imposed on th...

Bach, Handel, and the Chevalier Taylor.

But to proceed, I have seen a vast variety of singular animals, such as dromedaries, camels, &c and particularly at Leipsick, where a celebrated master of music, who had already arrived to his 88th year, received his sight by my hands; it is with this very man that the famous Handel was first educated, and with whom I once thought to have had the same success, having all circumstances in his fa...